iOS build errors - v0.1.1

flutter_crashlytics

Flutter plugin to enable Crashlytics reporting.

Setup

Firebase Crashlytics

If you're using Firebase instead of Fabric, you must first setup your app to use Firebase as per this tutorial. https://codelabs.developers.google.com/codelabs/flutter-firebase/#4

The instructions are the same for Fabric and Firebase, except that for Firebase, you don't get an API key so you don't have to add it anywhere.

Android

To setup Crashlytics on Android side, you need to set the Fabric ID in your manifest like this: (Only do this if using Fabric, not Firebase as you will not have an API Key)

 <meta-data
            android:name="io.fabric.ApiKey"
            android:value="YOUR_ID_HERE" />

You also need to change your build.gradle file like this:

buildscript {
    repositories {
        ...
        maven { url 'https://maven.fabric.io/public' }
    }

    dependencies {
        classpath 'io.fabric.tools:gradle:1.+'
        ...
    }
}

And apply the fabric plugin apply plugin: 'io.fabric'

Nothing more.

Symbolicating Native Android Crashes

Unfortunately, even pure Dart projects can't always protect you from native crashes. Without the following setup, a native crash like SIGSEGV will appear as a blank stacktrace in Crashlytics. Here's how to get some symbols:

Add the following to build.gradle, after apply plugin: 'io.fabric':

crashlytics {
    enableNdk true
    androidNdkOut "../../debugSymbols"
    androidNdkLibsOut "../../build/app/intermediates/transforms/stripDebugSymbol/release/0/lib"
}

Ensure that the NDK bundle is installed or the stripDebugSymbol directory won't get created.

Now setup a release script to populate the debugSymbols directory, guided by the instructions from https://github.com/flutter/flutter/wiki/Crashes

# Build our app like usual
flutter -v build apk --release

### BEGIN MODIFICATIONS

# Copy mergeJniLibs to debugSymbols
cp -R ./build/app/intermediates/transforms/mergeJniLibs/release/0/lib debugSymbols

# The libflutter.so here is the same as in the artifacts.zip found with symbols.zip
cd debugSymbols/armeabi-v7a

# Download the corresponding libflutter.so with debug symbols
ENGINE_VERSION=`cat $HOME/flutter/bin/internal/engine.version`
gsutil cp gs://flutter_infra/flutter/${ENGINE_VERSION}/android-arm-release/symbols.zip .

# Replace libflutter.so
unzip -o symbols.zip
rm -rf symbols.zip

# Upload symbols to Crashlytics
cd ../../android
./gradlew crashlyticsUploadSymbolsRelease

### END MODIFICATIONS

# Release your app like usual
cd ../..
fastlane submit_playalpha

iOS

On iOS side you need to set your Fabric ID under your Info.plist like: (Only do this if using Fabric, not Firebase as you will not have an API Key)

<key>Fabric</key>
    <dict>
        <key>APIKey</key>
        <string>YOUR_ID_HERE</string>
        <key>Kits</key>
        <array>
            <dict>
                <key>KitInfo</key>
                <dict/>
                <key>KitName</key>
                <string>Crashlytics</string>
            </dict>
        </array>
    </dict>

Turn off automatic collection with a new key to your Info.plist file (GDPR compliency if you want it):

Key: firebase_crashlytics_collection_enabled

Value: false

Don't forget to add your Run Script step (with any version of Xcode) on the build phases tab. If using Xcode 10, you also must add your app's built Info.plist location to the Build Phase's Input Files field:

$(BUILT_PRODUCTS_DIR)/$(INFOPLIST_PATH)

That's it :)

Flutter

All you need to do under your code is to let the plugin handle the Flutter crashes.

Your main method should look like:

void main() async {
  bool isInDebugMode = false;

  FlutterError.onError = (FlutterErrorDetails details) {
    if (isInDebugMode) {
      // In development mode simply print to console.
      FlutterError.dumpErrorToConsole(details);
    } else {
      // In production mode report to the application zone to report to
      // Crashlytics.
      Zone.current.handleUncaughtError(details.exception, details.stack);
    }
  };

  await FlutterCrashlytics().initialize();

  runZoned<Future<Null>>(() async {
    runApp(MyApp());
  }, onError: (error, stackTrace) async {
    // Whenever an error occurs, call the `reportCrash` function. This will send
    // Dart errors to our dev console or Crashlytics depending on the environment.
    await FlutterCrashlytics().reportCrash(error, stackTrace, forceCrash: false);
  });
}

forceCrash allows you to have a real crash instead of the red screen, in that case the exception will be tagged as fatal.

API available

Add log to crash reporting with log(String msg, {int priority, String tag})
Add manual log to crash reporting with logException(Error/Exception exception, Stacktrace stack)
Add user info to crash reporting with setUserInfo(String identifier, String email, String name)
Add general info to crash reporting with setInfo(String key, dyncamic value)

Limitation

This plugin uses Crashlytics SDK to log manual dart crashes, all manually logged crashes are tagged as non fatal under Crashlytics, that's a limitation of the SDK.

You can bypass that limitation with the forceCrash parameter, instead of the red screen an actual crash will be appended, the crash will be tagged as fatal.

On iOS fatal crash has their dart stacktrace under the Logs tab of Crashlytics, that's a limitation of iOS that prevents developers to set a custom stacktrace to an exception.